1. 根目录:
2. include
3. linux
4. netfilter_ipv6.h

#ifndef __LINUX_IP6_NETFILTER_H
#define __LINUX_IP6_NETFILTER_H

/* IPv6-specific defines for netfilter. 
 * (C)1998 Rusty Russell -- This code is GPL.
 * (C)1999 David Jeffery
 *   this header was blatantly ripped from netfilter_ipv4.h 
 *   it's amazing what adding a bunch of 6s can do =8^)
 */

#include <linux/netfilter.h>

/* only for userspace compatibility */
#ifndef __KERNEL__
/* IP Cache bits. */
/* Src IP address. */
#define NFC_IP6_SRC              0x0001
/* Dest IP address. */
#define NFC_IP6_DST              0x0002
/* Input device. */
#define NFC_IP6_IF_IN            0x0004
/* Output device. */
#define NFC_IP6_IF_OUT           0x0008
/* TOS. */
#define NFC_IP6_TOS              0x0010
/* Protocol. */
#define NFC_IP6_PROTO            0x0020
/* IP options. */
#define NFC_IP6_OPTIONS          0x0040
/* Frag & flags. */
#define NFC_IP6_FRAG             0x0080


/* Per-protocol information: only matters if proto match. */
/* TCP flags. */
#define NFC_IP6_TCPFLAGS         0x0100
/* Source port. */
#define NFC_IP6_SRC_PT           0x0200
/* Dest port. */
#define NFC_IP6_DST_PT           0x0400
/* Something else about the proto */
#define NFC_IP6_PROTO_UNKNOWN    0x2000

/* IP6 Hooks */
/* After promisc drops, checksum checks. */
#define NF_IP6_PRE_ROUTING	0
/* If the packet is destined for this box. */
#define NF_IP6_LOCAL_IN		1
/* If the packet is destined for another interface. */
#define NF_IP6_FORWARD		2
/* Packets coming from a local process. */
#define NF_IP6_LOCAL_OUT		3
/* Packets about to hit the wire. */
#define NF_IP6_POST_ROUTING	4
#define NF_IP6_NUMHOOKS		5
#endif /* ! __KERNEL__ */


enum nf_ip6_hook_priorities {
	NF_IP6_PRI_FIRST = INT_MIN,
	NF_IP6_PRI_CONNTRACK_DEFRAG = -400,
	NF_IP6_PRI_RAW = -300,
	NF_IP6_PRI_SELINUX_FIRST = -225,
	NF_IP6_PRI_CONNTRACK = -200,
	NF_IP6_PRI_MANGLE = -150,
	NF_IP6_PRI_NAT_DST = -100,
	NF_IP6_PRI_FILTER = 0,
	NF_IP6_PRI_SECURITY = 50,
	NF_IP6_PRI_NAT_SRC = 100,
	NF_IP6_PRI_SELINUX_LAST = 225,
	NF_IP6_PRI_LAST = INT_MAX,
};

#ifdef  __KERNEL__

#ifdef CONFIG_NETFILTER
extern int ip6_route_me_harder(struct sk_buff *skb);
extern __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
				    unsigned int dataoff, u_int8_t protocol);

extern int ipv6_netfilter_init(void);
extern void ipv6_netfilter_fini(void);
#else /* CONFIG_NETFILTER */
static inline int ipv6_netfilter_init(void) { return 0; }
static inline void ipv6_netfilter_fini(void) { return; }
#endif /* CONFIG_NETFILTER */

#endif /* __KERNEL__ */

#endif /*__LINUX_IP6_NETFILTER_H*/